Article excerpt

At Petrolite Corp.'s headquarters, two companies are using
genetically engineered bacteria to remove sulfur from oil.

If successful, they could combat one of nature's most abundant
elements and pervasive pollutants.

Sulfur-laden crude oil is an expensive problem for oil
companies because it corrodes refining equipment. When burned, this
oil produces sulfur oxides that are linked to smog and acid rain.

But in the presence of certain bacteria, the sulfurous oil
becomes a grand repast.

So Petrolite has joined a Texas company to see if biotechnology
and oil-purification skills can produce a new way to make cleaner
oil by creating bacteria with bigger appetites.

The driving force is Energy BioSystems Corp. of suburban
Houston. Founded in 1989, the company is training a bacterium to
pry away sulfur bound to petroleum - without damaging the quality
of the oil.

The bacterium - Rhodococcus erythropolis - is found in soil and
has a natural affinity for sulfur.

Manufacturers have used it for more than 40 years to produce
items as varied as citric acid and vitamins, said Daniel J.
Monticello, vice president of research and development for Energy
BioSystems.

Around oil, Rhodococcus is a scavenger because it needs sulfur
to survive. "We have to convince the bacteria that this is the most
important thing they can do," Monticello said.

Energy BioSystems does this by manipulating the bacterium's
genes, isolating sulfur-eating enzymes. The natural bacterium is
not aggressive enough in producing the enzymes.

"We need to get the organisms to sprint," Monticello said.
"Right now, they're jogging. When we started, they were crawling."

The jazzed-up bacteria are cultivated, mixed with water and
then combined in a special reactor with a stream of high-sulfur oil.

The oil passes through the reactor; the bacteria chow down,
pulling the sulfur from the oil.

The oil is funneled from the reactor while the sulfur byproduct
is removed. The water and bacteria are recycled into the reactor.

That's how it works in the laboratory, and now it's being
tested in a two-story pilot plant at Petrolite's headquarters. The
pilot plant started in March, and the two companies conducted a
tour for securities analysts and the media Tuesday.

Energy BioSystems officials say they will know by the end of
the year if the pilot plant works well enough to build a
full-scale plant. …